The best camera you have is the one in your hands at the time.
Understanding the strengths and weaknesses of the tools in your hands at the time and how to get the best out of them is what separates a professional from an amateur (or as my mother would say, it's a poor craftsman who blames his tools).

A few interesting points:
Only 2048x1024 in resolution for the final product- so the loss of detail isn't a concern.
A defined horizon at the 50% mark of the frame.

Question:
Concerns about spherical projection or other lens distortions?

My solution:
What I'd do is fairly simple, use the 14mm lens on the trippod, with the camera held at the 90 orientation, shoot overlapping photos at every 15 degrees, left to right (0, 15, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180). and then use autostitch (AutoStitch) to make your panorama photo, and then rescale to size.

For those who do not know how to read the information being shown:
The row header is the hex offset, 0 to 15 (or 1 to 16).
The column is the memory offset of the program, starting at 0000 and ending.
The first set of characters is A0 (space) and 00 (null). The 94s in the second set are a nothing character.

Hire a lawyer to get legal advice.
While at it, have them draft up a template contract that you can use for your gigs, form a LLC for your business, and establish yourself properly.
If you've already gone this route, and feel that you've undercharged, consider this as a learning experience in negotiations.

Or, do the job under the table, consider the job as a work for hire and assign the copyrights to the Golf & Country Club.

I've been on both sides of the deal and it's painful to learn these things first time out (especially in saying "No").
Good luck!

You can push the Kodak Tri-X quite a bit; back in 2000 I was hiking around France and used a few rolls under the summer sun at ISO-100 with a Red-90 filter in place.
You'll be shooting with an F5.6 to F8 (or better), the film certainly can take that.
Also, just for giggles, here's two photos I took in Boston from 1999 / 2000 using Kodak's Color IR film.

Surprisingly little horse power is required to encode & decode H.265, any computer from the last 10 years will mange, certainly anything within the last 5.
Hardware acceleration of the decoding is useful, but only with edge cases (you're not re-encoding 50 years of ABC TV are you?), certainly more memory is useful (but can your OS use the extra RAM), faster IO is always better, but for a home user, you'll get by.

As you pointed out VLC does a good job with both; I would stick with it as the preferred playback tool.

For what it's worth, reading the user manual for the K-1, page 119, the movie recording format is MPEG-4 AVC/H.264 (MOV).
Of course, on the flip side, Apple is End Of Life QuickTime on Windows PCs.

Personally, I am on the fence with the two dial controls. Redundancy of functions, and crowding of the top are my largest issues, and frankly a few of those settings I feel are better placed in a menu item (WiFi for example; if you are going to be using it, your going to have it already setup and on before the first shot is taken). It feels like control overload. It could be simpler, easier.

Grid is the most interesting to me, I wonder if Pentax will allow for a custom grid to be loaded into the system, and what grids are already there?
I mainly use the rule of 3rds for composition, but I would love to add to it the golden ratio, nautilus spiral overlay, or a ring overlay. The only down side is using a manual focus split prism is out of the question.

Having actually shot using blacklights for lighting, I can tell you that there are a few things that you'll need to do to do this right.
Blacklight is extremely hard to focus under (it's dark), so have a flashlight to assist with the focusing if you're using autofocus, otherwise manual focus is best, and a tripod is required.
Blacklights do not put out a lot of light. Think what you're going to need to light the room up and double or triple it. A place to get a blacklight is Hot Topic (they sell the 48" tube and a fixture. Amazon probably has a good deal more.).
UV reactive makeup is around, you'll want some. In our case it wore off quickly and we had to reapply often. White clothing reflects the best. A good black backdrop helped too.
Your eyes will get tired, best to give yourself some breaks.

A caveat is that I took these with my K-20 way back in the day. -- correction; EXIF is saying my wife's K5. Okay then.

Lucky you- France is a beautiful country, and I strongly agree with everyone that there is so much more to see and do outside of Paris.
My suggestions for places to visit and photograph in France would include:
Provins - Only one hour by local train just outside of Paris (South East). Famous for it's old wall city, brie cheese, flour, and roses. My wife and I where married here (we eloped).
Reims - The champagne houses and the cathedral are very impressive.
Chamonix (and the three valleys) - French Alps at it's finest.
Cassis - On the Mediterranean coast, famous for it's calanques (fjords), just east of Marseilles. Worth a few days (and if you don't mind roughing it, stay at the hostel in the Calangue park, great vista of Cassis and the cliffs that hang over it.).
Toulouse - Take A66 towards the Andorra. Incredible drive, lots of great photo opportunities.

In Paris - I've found the 19th Arrondissement (specially the Cite des Sciences et de I'Industri) to very photogenic. Easy to walk down the canal.
Also, the 18th, Sacre-Coeur, yeah, a little cliched, but worth it.
La Defense is interesting place to see, nice modern architecture.
South of the city is Observatoire de Paris, 18th century science hall, along with lovely gardens.
Versailles, it will be crazy, and nearly too much to take in (weekday if you are going).

Yes, all the time actually.
With a few caveat, naturally- first I put the strap around their neck, so I'm ensure that if they let go of the camera that it's not going anywhere, then I give them a really quick lesson on how the camera is configured (look though the diopter, how to adjust the diopter, and how the focus is setup).
Then I relax, and enjoy being in the shot.

But! This is me and my wife, we're cool with it.
_If_ you don't feel good about handing over the camera, then don't.
No one is going to feel bad about you saying no.

I use a Synology DS+1513 NAS with a full 20 TB (5x4TB) of disk installed (after RAID, 14TB usable). $1500 from B&H.
It provides a good storage / backup solution for my needs. It is fast (I can burn a DVD from the NAS faster than from my own HD).
It is expandable, both with larger HDs and external expansion units (> 60TB max space with 2 expansion units).
It is very user friendly, and I'm very happy with it.

You either want an Ikelight or Sea and Sea hard case housing for any serious water works. I know that Ikelight use to make for the K-5 a housing, but have since discontinued it.
Bags are okay, but I would not trust one beyond 20 feet (5m) deep

A couple of quick questions:
Is the place well lit? Will you have room to move around and photograph people?
The 50mm is nice, specially if the room is dark, but the major trade off is that you'd only get one viewing angle, and you'll have a harder time shooting around people. The 12-35 is better to grab groups of people, but if the place is dark or low light, a flash is going to be required.
I usually use the following settings for evening party shots: ISO 800 to 1600, 1/60 to 1/160, bounce flash if the ceiling isn't way up there, and my 24-70mm f2.8 (Sigma). Sometimes I'll put on the 50mm prime (also Sigma), if I can walk around the room easily.
Very rarely will I bring both lens along and change them to get a shot.

The photo below, of a friend, was taken at a bar this past November, using the 50mm lens, ISO 800, 1/125, no flash, DNG. Some minor Photoshop'ing to adjust colors and crop the photo.